Peter Sarsgaard, the actor hubby of Maggie Gyllenhaal, used to be quite the ladies’ man in high school.

“I put a sofa on my roof as a kid, ran an electric cord up to it, had two jacks — one connected to an electric blanket and one connected to a radio. I became a very popular person,” he told us at a Forevermark screening of his new film, “Night Moves,” at Landmark’s Sunshine Cinema Tuesday, explaining his parents “didn’t even know the sofa was up there for, like, half a year.”